A blast gauge comprising a spherical fairing containing four pressure sensors whose positions on the surface of the sphere form the apices of a tetrahedron is described in United Kingdom patent 2 246 861. See also, Edwards, U.S. Ser. No. 07/969,159, U.S. Pat. No. 5,435,178. The gauge is a non-directional device which will record the amplitude of a blast wave regardless of its orientation. The gauge is also capable of providing directional information for each wave reaching it. The signals from pressure sensors in the gauge are fed to signal processing means where the amplitude of the incident pressure on each sensor and its time of occurrence are stored. The stored information may be used to provide details of the amplitude and direction of successive blast waves which fall on the gauge following an initial event.
The above described equipment provides azimuth (bearing) information only on the path of a missile. The source of the missile has to be estimated by visual assessment of the terrain involved.
See also, The Sunday Times, Jun. 19, 1994, "Bullet direction finder shows where the snipers are hiding."